I just jumped on the hi-fi wagon this weekend, and it is well worth it. If you're living in the US you are very lucky as I got screwed over with pricing in Canada. Bookshelves are especially strong in music, but they are just as detailed in games. Going from computer speakers to shelves, the soundstage is huge, everything is more directional and crisper. You can probably get a refurbed Onkyo receiver($100-$200) like others have said, and go for some 'budget' speakers such as the Infinity P150 (great value in US, rip off in Canada), Athena AS-B1 (same), Paradigm Atoms or really really cheap Insignias from Best Buy if they're available; all are around $100-$150 -ish US. These may be budget, but blow any computer speakers away. If you want to upgrade, you can move front speakers to different positions (rear) or use them for another setup. Also, these can be continually upgraded, but those two computer speaker sets are it. There is nothing past the Ultras or Creatives in terms of quality.
However, just remember that the price you pay for 2.0 bookshelves and receiver will be the same as those 5.1/7.1 setups. That and if you're use to having a computer sub, you WILL miss it a lot if you don't get start with at least 2.1 (I never knew what a difference the sub made, and now I need one🙁). Also a note on the Klipsch Ultras: they seem to have a huge design defect/flaw that causes more than an acceptable number of blowouts, which you probably have to pay for. Just check their official forums. If you need more 'literature':Q, go check out tomshardware or sharkyextreme sound forums. Regardless, good luck on whatever you decide.
